Hey there, I am a nanny to an 8 month old little girl. I COMPLETELY understand where you are coming from. My DB is a pediatrician and MB is a surgeon. I had a similar experience when my charge was 4 months old and did end up approaching MB. I am so glad I did. As doctors, they were the first to say they weren't as concerned and wanted to stay away from antibiotics if possible, but she has a sinus infection and once on antibiotics it cleared up quickly. I would definitely mention your concern. Green mucus generally means infection. Poor baby

I hope he feels better soon!! good luck!!